The Northern Collector Tunnel that is set to pump 140 million litres of water daily into Nairobi is now 98 per cent complete.
The multi-billion project is slated to be completed in July but the government is pushing for a June deadline.
The tunnel will channel water drawn from rivers Gikigie, Irati and Mathioya into Ndaka-ini dam.
The water will then be processed at Kigoro treatment plant, which acting Water CS James Macharia has confirmed is complete.
Macharia said the project is key to the Jubilee government as it is one of President Uhuru Kenyatta's flagship projects.
The CS spoke on Thursday while inspecting the project.
He said water rationing, which has been affecting majority of Nairobi residents will be history once the project is complete.
The project has three components, the tunnel, treatment plant and pipeline from the treatment plant to Gigiri reservoir in Nairobi.
The 11.8km tunnel has been financed by the French Development Agency at a cost of Sh8.2 billion.
It was started in 2015 and is only pending the installation of intake gates.
Macharia said the treatment plant is waiting for the tunnel to become operational and start channeling.
The project will also supply 10 million litres of water daily to Gatanga residents to compensate them for the project.
Residents led by MP Nduati Ngugi had for years complained that they were still trekking long distances to rivers to fetch water despite hosting the largest dam in the country.
"We are here to ensure the project is going on well and to brief the President who is keen that it is completed on time," Macharia said.
He said water for both irrigation and domestic use is critical to foster development of the country.
The commodity is especially vital for the capital city that generates about 50 per cent of the country's Gross Domestic Product.
The city, Macharia said, has a daily water demand of 810 million litres but the government is only able to supply 560 million litres, creating a deficit of about 250 million litres.
"Providing sufficient water to the city is the government's way of supporting the economy. We can't go far if we are unable to offer such support," he said.
The CS said the government has a policy to ensure all parts of the country are provided with the commodity.
He said all ministries have been co-operating to ensure water towers are protected and conserved even as projects are implemented.
"That is why when we were doing the Mau Mau roads. We changed the design to ensure we don't go through the Aberdare forest," Macharia who also doubles up as the Roads CS said.
However, Athi Water Works CEO Mwangi Thuita said the third component of the project, the Ndaka-ini Kigoro Gigiri water transmission pipeline is 36 per cent complete.
"The scope of works include laying of 5.4 km raw water pipeline from Ndaka-ini dam to Kigoro treatment plant. Also a 49 km treated water pipeline between Kigoro Water Works and Nairobi Gigiri reservoirs," he said.
Thuita however said 20.7 kms of pipeline have been laid.
He said the project is now facing wayleave challenges requiring the ex-chequer to release Sh2 billion.
Last June, the CEO said the Chinese contractor was yet to be reimbursed Sh724 million for VAT by the government.
Thuita however said all administrative issues pertaining to the project have been sorted.
(Edited by Bilha Makokha)
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